As a constant velocity universal joint to be used as a unit configured to transmit rotational torque from an engine of an automobile to a wheel at a constant velocity, there are given, for example, two kinds, specifically, a fixed type constant velocity universal joint and a plunging type constant velocity universal joint. Both of the constant velocity universal joints have a structure in which two shafts on a driving side and a driven side are coupled to each other to allow rotational torque to be transmitted at a constant velocity even when each of the two shafts forms an operating angle.
In a drive shaft configured to transmit power from an engine of an automobile to a driving wheel, it is necessary to support angular displacement and axial displacement caused by a change in relative positional relationship between the engine and the wheel. Therefore, in general, the plunging type constant velocity universal joint is mounted on an engine side (inboard side), and the fixed type constant velocity universal joint is mounted on a driving wheel side (outboard side), and both of the constant velocity universal joints are coupled to each other through intermediation of an intermediate shaft.
In the plunging type constant velocity universal joint or the fixed type constant velocity universal joint, in order to prevent entry of foreign matters from outside of the joint as well as leakage of a lubricant, for example, a grease sealed in the joint, a boot is mounted between an outer joint member of the constant velocity universal joint and the intermediate shaft. This type of boot is fastened with a metallic boot band (see, for example, Patent Literatures 1 to 4) to be fixed to the outer joint member and the intermediate shaft, thereby ensuring a sealing property.
As illustrated in FIG. 7, a fastening band disclosed in Patent Literature 1 is a hose band to be used under a state in which a belt-like member 1 is rolled up into a ring shape so that both end portions thereof are overlapped on one another on an inner side and an outer side. This band includes engagement holes 2 in an outer overlapped portion 1a of the belt-like member 1, and protrusions 3 configured to be engaged with the engagement holes 2 in an inner overlapped portion 1b of the belt-like member 1. The band further includes a fastening ear portion 4 in a part of the belt-like member 1 in a longitudinal direction thereof. Further, a distal end portion 5 of the inner overlapped portion 1b is formed into a tapered shape having a reduced thickness on the distal end side, and a punched hole or a cutaway hole is formed in the distal end portion 5. The diameter of the band is reduced by plastically deforming the ear portion 4.
As illustrated in FIG. 8, a band described in Patent Literature 2 has the following configuration. A metallic band 6 having a band shape is rolled up so that both end portions thereof are overlapped on one another. Engagement holes 9 and a caulking protrusion 7 that rises in a radially outward direction through bending are formed in an outer overlapped portion 6a of the band 6, and cut and raised protrusions 10 configured to be engaged with the engagement holes 9 are formed in an inner overlapped portion 6b of the band 6. Further, a protrusion 11 that is opposed to a distal end of the inner overlapped portion 6b at an interval corresponding to the caulking amount of the caulking protrusion 7 is formed on an inner surface of the outer overlapped portion 6a so that the inner surface of the protrusion 11 is connected to a cylindrical inner surface of the band 6, and the height of the protrusion 11 at the distal end is set to be equal to or more than the thickness of the band 6. Also in this case, the diameter of the band 6 is reduced by plastically deforming the caulking protrusion 7.
As illustrated in FIG. 9A, a band described in Patent Literature 3 has the following configuration. Engagement claws 16 and a first tool claw 17 are formed in an inner overlapped portion 15b of a belt-like member 15, and engagement holes 19 and a second tool claw 20 are formed in an outer overlapped portion 15a of the belt-like member 15. As illustrated in FIG. 9B, the first tool claw 17 and the second tool claw 20 are forcibly brought into close to each other to engage the engagement claws 16 and the engagement holes 19 with each other.
As illustrated in FIG. 10A and FIG. 10B, a band disclosed in Patent Literature 4 includes temporary retaining protrusions 22 configured to keep a temporary retained state in which a belt-like member 15 is wound around an outer periphery of a boot and a lock protrusion 23 configured to keep a fastened state of the belt-like member 15 fastened in a diameter reducing direction from the temporary retained state. Further, protruding portions 24 configured to regulate freewheeling of the belt-like member 15 with respect to the boot are formed along a length direction of an inner overlapped portion. Also in this case, the diameter of the band is reduced by forcibly bringing a first tool claw 17 formed in an inner overlapped portion 15b and a second tool claw 20 formed in an outer overlapped portion 15a into close to each other.